A Russian anti-drug unit has stumbled across radioactive soil samples from the site of the 1986 Chernobyl nuclear disaster as well as some dangerous traces of plutonium, officials said Thursday.

Drug police discovered several canisters of soil "that probably came from Chernobyl" and an undisclosed amount of the dangerous substance used as fuel in nuclear power plants, a spokesman for the Federal Drug Control Service said.

The unusual find came in the vehicle of one of the suspects of a gang that ran an underground laboratory for making amphetamines and other drugs, the spokesman told AFP by telephone.

Officials promised to release more details about the men they had arrested and their possible motives next week. The drug agency spokesman said official could be dealing with militants, but did not give any further details.